The invention relates to aircraft towing vehicles.
A previously tested prototype of a towing vehicle of the general type under consideration herein, which was reported in the media, has a lifting mechanism tiltably mounted on a carrier that is pivotable at its front end. As a result, the mechanism can readily adjust itself to the contour of a nose wheel as it approaches the latter. However, this adjustment of the lifting mechanism is achieved only partially and over only a small angular extent of the wheel for nose wheels having widely varying diameters. This observation applies also to the towing vehicle disclosed in German Patent Publication DE-OS No. 35 34 045, but never actually built, in which the lifting mechanism according to FIG. 5 is also tiltably mounted on an advancing lever for the mechanism, while, according to FIG. 3, the lifting mechanism is constructed as a flat roller plate that has only point contact with the nose wheel.
Ideally, when engaging the nose wheel, the lifting mechanism should grip it at the lowest possible point to convert the advancing force applied to the mechanism as effectively as possible into a wheel lifting thrust. After securing the wheel, however, the mechanism should engage the wheel at as high a point as possible so that it effectively cooperates with the wheel hold-down device to prevent relative movement of the nose wheel in an upward direction. Prior art lifting mechanism fail to meet these requirements, especially when they are adapted for use with nose wheels of widely varying diameters.